All commands are done through the Console. Must be enabled through the -Console
option on an shortcut to the game executable or enabled in the in game options
under the Advanced section of Controls. It is then accessed by pressing the
tilde key (next to numeric one on NTC keyboards, on the right side somewhere on
the freak -- PAL --keyboards).

Most of these require sv_cheats to be set to 1.

upgrade_portalgun - Allows use of second portal placement. Must have obtained
blue portal portion of the gun.
fire_energy_ball - Fires an energy ball that can be used in solving puzzles.
Recommend that you bind this to a key for easy use. Example would be, bind q
fire_energy_ball
ent_create_portal_weight_box - Creates a Weighted Storage Cube for your use in
getting a little bit higher, holding down a button, or taking out a sentry.
change_portalgun_linkage_id # - Replace # with an integer from 0 to 3. Allows
for creation of seperate sets of portals.
sv_portal_placement_never_bump 1 - No listed effect.
sv_portal_placement_never_fail 1 - Portals can be placed on almost any surface.
They still cannot go through the dispersal fields and some curved
surfaces/models.